As for "why does it look like that"... I'm only guessing, mind you, but I suspect that this "coin" was made to be attached to something: a medallic piece of jewellery, a piece of furniture, a book, or perhaps one of those bowls-with-a-coin-in-the-bottom-of-it that you can buy in numerous touristy places in Latin America. The star-sail pattern would therefore be intended to adhere to whatever glue or solder might have been used to attach this piece to whatever it was supposed to be attached to.
A similar example: there is an
extremely commonly encountered fake ancient coin that has a huge hole in the design on one side of it. These replicas were originally attached to a piece of cardboard, and the hole was placed there by whoever made the replicas to allow the blob of glue to form a better bond between the coin and the card.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis